AES E-Library

MPEG-4 Audio Lossless Coding (ALS) is a new extension of the MPEG-4 audio coding family. The MPEG-4 ALS codec is based on forward-adaptive linear prediction, which enables remarkable compression even with low complexity. Additional features include long-term prediction, multichannel coding, and compression of floating-point audio material. In this paper authors who have actively contributed to the standard describe the basic elements of the ALS codec with a focus on prediction, entropy coding, and related tools. It also presents latest developments during the standardization process and points out the most important applications of this new lossless audio format.